Release of fuel-bound nitrogen during biomass gasification

Gasification of four biomass feedstocks (leucaena, sawdust, bagasse, and ba nagrass) with significantly different fuel-bound nitrogen (FBN) content was investigated to determine the effects of operational parameters and nitrog en content of biomass on the partitioning of FBN among nitrogenous gas spec ies. Experiments were performed using a bench-scale, indirectly heated, flu idized-bed gasifier. Data were obtained over a range of temperatures and eq uivalence ratios representative of commercial biomass gasification processe s. An assay of all major nitrogenous components in the gasification product s was performed for the first time, providing a clear accounting of the evo lution of FBN. Important findings of this research include the following: ( 1) NH3 and N-2 are the dominant species evolved from fuel nitrogen during b iomass gasification; >90% of FBN in feedstock is converted to NH3 and N-2; (2) relative levels of NH3 and N-2 are determined by thermochemical reactio ns in the gasifier; these reactions are affected strongly by temperature; ( 3) N-2 appears to be primarily produced through the conversion of NH3 in th e gas phase; (4) the structural formula and content of fuel nitrogen in bio mass feedstock significantly affect the formation and evolution of nitrogen species during biomass gasification.